Digital Commons Network^™

Coherent States Of The Laguerre–Gauss Modes, M. P. Morales Rodríguez, O. S. Magaña-Loaiza, B. Perez-Garcia, L. M. Nieto Calzada, F. Marroquín Gutiérrrez, B. M. Rodríguez-Lara

Faculty Publications

Large quantum photonic systems hold promise for surpassing classical computational limits, yet their state preparation remains a challenge. We propose an alternative approach to study multiparticle dynamics by mapping the excitation mode of these systems to physical properties of the Laguerre–Gauss modes. We construct coherent states establishing a direct link between excitation number dynamics and the evolution of the Laguerre–Gauss modes. This highlights the photon transverse spatial degree of freedom as a versatile platform for testing the fundamental aspects of quantum multiparticle systems.

Hydroxymethanesulfonate And Sulfur(Iv) In Fairbanks Winter During The Alpaca Study, Kayane Dingilian, Elliana Hebert, Michael Battaglia Jr., James R. Campbell, Meeta Cesler-Maloney, William Simpson, Jason M. St. Clair, Jack E. Dibb, Brice Temime-Roussel, Barbara D’Anna

Faculty Publications

Hydroxymethanesulfonate (HMS) in fine aerosol particles has been reported at significant concentrations along with sulfate under extreme cold conditions (-35 °C) in Fairbanks, Alaska, a high latitude city. HMS, a component of S(IV) and an adduct of formaldehyde and sulfur dioxide, forms in liquid water. Previous studies may have overestimated HMS concentrations by grouping it with other S(IV) species. In this work, we further investigate HMS and the speciation of S(IV) through the Alaskan Layered Pollution and Chemical Analysis (ALPACA) intensive study in Fairbanks. We developed a method utilizing hydrogen peroxide to isolate HMS and found that approximately 50% of …

Whole-Of-School Physical Activity Implementation In The Context Of The Dubai Fitness Challenge, Chris Mcmahon, Collin A. Webster, Robert Weaver, Christophe El Haber, Gönül Tekkurşun Demir, Zainab Mohamed Ismail, Syeda Zoha Fatima Naqvi, Mehnaz Ghani, Şevval Kepenek, Manel Kherraf, Thrisha Krishnakumar, Pranati Prakash, Yeowon Seo

Faculty Publications

Introduction

Physical activity (PA) promotion among school-aged youth is a global health priority. Recommendations for such promotion include implementing whole-of-school approaches that maximize resources across the school environment. This study examined schools’ participation in an annual, government-led, and emirate-wide initiative in Dubai, called the Dubai Fitness Challenge, in which the goal is to accrue 30 minutes of PA every day for 30 days (as such, the initiative is colloquially referred to as “Dubai 30x30”).

Methods

A mixed-methods design was employed for this study. Three schools were recruited using convenience sampling. Participants were 18 physical education teachers, 20 classroom teachers, 2 …

Reconsidering The Reliability Of Chemical Process Simulators I: Implementation Of The Murphree And Vaporization Efficiencies, Zachary Braswell, Brian F. Hanley, Holt Ragsdale

Faculty Publications

Most chemical process simulators in widespread use today allow users to apply some type of efficiency correction to individual equilibrium stages or to equilibrium stage sections in order to align the stage or section separation performance more closely to actual tray performance in the field. Some simulators even allow for the use of component efficiencies on individual stages or in stage sections. It is our contention, however, that two of the more commonly available efficiency models, the vaporization efficiency and Murphree vapor phase efficiency, have generally been implemented incorrectly. The three major conceptual inconsistencies are (1) the assumption that the …

Modulation Of Methoxyfenozide Release From Lignin Nanoparticles Made Of Lignin Grafted With Pcl By Rop And Acylation Grafting Methods, Alvaro Garcia, Carlos E. Astete, Rafael Cueto, Cristina M. Sabliov

Faculty Publications

An efficient and sustainable agriculture calls for the development of novel agrochemical delivery systems able to release agrochemicals in a controlled manner. This study investigated the controlled release of the insecticide methoxyfenozide (MFZ) from lignin (LN) nanoparticles (LNPs). LN-grafted poly(ϵ-caprolactone) (LN-g-PCL) polymers were synthesized using two grafting methods, ring-opening polymerization (ROP)(LN-g-PCLp) and acylation reaction (LN-g-PCLa), creating polymers capable of self-assembling into nanoparticles of different properties, without surfactants. The LN-g-PCLp polymers exhibited a degree of polymerization (DP) from 22 to 101, demonstrating enhanced thermal stability after LN incorporation. LNPs loaded with MFZ exhibited a spherical core-shell structure with a hydrophilic LN …

Growing New Librarians Through Meaningful Internships, Nicole Lewis

Faculty Publications

Internships have the potential to be incredible learning experiences for students, but without thoughtful preparation, they may be nothing more than short-term jobs. Using a metadata internship as a case study, this presentation will discuss how using effective teaching and course design principles could create more thoughtful and meaningful internship experiences, specifically how crafting an internship objective and learning outcomes can help with creating content and learning activities that prepare interns for their hands-on projects. The result is an internship that combines theory and practice into a meaningful experience for the student and delivers needed work for the library.

Pal-Bert: An Improved Question Answering Model, Wenfeng Zheng, Siyu Lu, Zhuohang Cai, Ruiyang Wang, Lei Wang, Lirong Yin

Faculty Publications

In the field of natural language processing (NLP), there have been various pre-training language models in recent years, with question answering systems gaining significant attention. However, as algorithms, data, and computing power advance, the issue of increasingly larger models and a growing number of parameters has surfaced. Consequently, model training has become more costly and less efficient. To enhance the efficiency and accuracy of the training process while reducing the model volume, this paper proposes a first-order pruning model PAL-BERT based on the ALBERT model according to the characteristics of question-answering (QA) system and language model. Firstly, a first-order network …

Simulations Of Langmuir-Wave Emission By Magnetic Holes In The Solar Wind, Jingting Liu, Daniel Verscharen, Jesse Coburn, Jeffersson Agudelo, Kai Germaschewski, Hamish Reid, Georgios Nicolaou, Christopher Owen

Faculty Publications

Langmuir waves are frequently detected in the solar wind and affect the energetics of the plasma electrons. Previous observational studies have found Langmuir waves associated with magnetic holes in the solar wind. In our work, we aim to understand the connection between magnetic holes and these waves. The Langmuir instability is a well-known consequence of electron beams in plasmas. We use particle-in-cell (PIC) simulations of a collisionless electron-ion plasma in a magnetic hole structure. We study the triggering of Langmuir waves by inhomogeneous beam instabilities in this configuration. Our simulations reveal patterns that suggest that injecting a beam into the …

Simulations Of Langmuir-Wave Emission By Magnetic Holes In The Solar Wind, Jingting Liu, Daniel Verscharen, Jesse Coburn, Jeffersson Agudelo, Kai Germaschewski, Hamish Reid, Georgios Nicolaou, Christopher Owen

Faculty Publications

Langmuir waves are frequently detected in the solar wind and affect the energetics of the plasma electrons. Previous observational studies have found Langmuir waves associated with magnetic holes in the solar wind. In our work, we aim to understand the connection between magnetic holes and these waves. The Langmuir instability is a well-known consequence of electron beams in plasmas. We use particle-in-cell (PIC) simulations of a collisionless electron-ion plasma in a magnetic hole structure. We study the triggering of Langmuir waves by inhomogeneous beam instabilities in this configuration. Our simulations reveal patterns that suggest that injecting a beam into the …

Examining The Impact Of Stream Permanence On Headwater Stream Carbon Emissions, Hannah D. Conroy, Erin R. Hotchkiss, Kaelin M. Cawley, Keli Goodman, Jeremy B. Jones, Wilfred M. Wollheim, David Butman

Faculty Publications

Quantifying headwater stream carbon emissions is important for our understanding of the global carbon cycle because these emissions (an estimated 0.93-1.15 Pg C year) can be substantial compared to the terrestrial flux. Headwater stream networks can have high emissions due to their coupling with the terrestrial environment and high turbulence with some estimates predicting headwater stream networks can contribute 70% of the global riverine stream emissions. These carbon emissions are challenging to predict, especially with regards to headwater stream network spatiotemporal heterogeneity. The majority of headwater streams exhibit changes in stream network area on a seasonal basis, and these locations …

The Myth Of Tightening Credit Rating Standards In The Market For Corporate Debt, Karolina Krystyniak, Viktoriya Staneva

Faculty Publications

This study revisits the existing evidence of a downward trend in credit rating standards indicating that CRAs have become more conservative over time. We find that the time-series variation in the proxy for rating standards is mostly driven by the market-based variables in the model, specifically market capitalization and idiosyncratic volatility. We examine an alternative specification of the model, incorporating risk characteristics of rated firms relative to those of the average firm in the economy, and find it to have a higher explanatory power. Most importantly, we find little evidence of increased conservatism over time, in contrast to prior studies.

The Myth Of Tightening Credit Rating Standards In The Market For Corporate Debt, Karolina Krystyniak, Viktoriya Staneva

Faculty Publications

This study revisits the existing evidence of a downward trend in credit rating standards indicating that CRAs have become more conservative over time. We find that the time-series variation in the proxy for rating standards is mostly driven by the market-based variables in the model, specifically market capitalization and idiosyncratic volatility. We examine an alternative specification of the model, incorporating risk characteristics of rated firms relative to those of the average firm in the economy, and find it to have a higher explanatory power. Most importantly, we find little evidence of increased conservatism over time, in contrast to prior studies.

Using Stereo-A Data From April To November 2023 As A Sub-L1 Monitor, Eva Weiler, Christian Möstl, Emma E. Davies, Tanja Amerstorfer, Ute V. Amerstorfer, Hannah T. Rüdisser, Rachel L. Bailey, Astrid Veronig, Timothy Horbury, Noé Lugaz, Justin Le Louëdec, Maike Bauer

Faculty Publications

Sub-L1 monitors are currently being researched in mission concepts for small satellites and may be deployed on distant retrograde orbits around the Earth in the future. Depending on the location of the sub-L1 monitor, the lead time for the arrival of coronal mass ejections (CMEs) and for determining their geo-effectiveness could be prolonged. If the sub-L1 monitor was to orbit the Earth at a distance of 0.05 AU, as is proposed for the MIIST mission, for example, Dst predictions could be made up to 5 hours in advance. The close encounter of STEREO-A and Wind from April 2023 to November …

The Space Weather Research On Coronal Mass Ejections Required Before Operational Sub-L1 Monitors, Noé Lugaz, Florian Regnault, Sahanaj Banu, Nada Al-Haddad, Bin Zhuang, Christina Lee, Charles J. Farrugia, Christian Möstl, Reka M. Winslow, Emma Davies, Camilla Scolini, Wenyuan Yu, Antoinette B. Galvin

Faculty Publications

In-situ measurements from the Sun-Earth Lagrangian L1 point typically provide a 20-minute to 1-hour advanced warning of incoming interplanetary (IP) shocks, magnetic clouds before impact at the nose of Earth's magnetopause. Sub-L1 monitors may provide measurements sunward of the L1 point to improve the lead times for such transients to several hours, and various mission architecture have been proposed for more than 25 years. Because CMEs and shocks do not propagate exactly radially, the location of such a monitor with respect to the Sun-Earth line is a key parameter to take into account when designing such missions. Here, we highlight …

Interactions Between Soil Mineral Composition And Particulate Organic Matter Mediate Bioavailable Nitrogen, Andrea Jilling, Marian Carrell, A Stuart Grandy, Rachel Hestrin, Marco Keiluweit, Erik Knatvold, Andrew Whitaker

Faculty Publications

Soil organic matter (SOM) can supply critical quantities of nitrogen (N) to plants, but fundamental questions remain regarding from what pools and by which processes plants and microbes obtain N. The source of bioavailable N is generally assigned to polymeric or particulate organic matter (POM), but in mineral soils, POM is often a minor pool of N and can be a poor predictor of bioavailable N or plant N uptake. Mounting evidence suggests mineral-associated organic matter (MAOM) is significantly more dynamic than previously assumed and may serve as an important source of N for plants and microbes. The abundance and …

Interactions Between Soil Mineral Composition And Particulate Organic Matter Mediate Bioavailable Nitrogen, Andrea Jilling, Marian Carrell, A Stuart Grandy, Rachel Hestrin, Marco Keiluweit, Erik Knatvold, Andrew Whitaker

Faculty Publications

Soil organic matter (SOM) can supply critical quantities of nitrogen (N) to plants, but fundamental questions remain regarding from what pools and by which processes plants and microbes obtain N. The source of bioavailable N is generally assigned to polymeric or particulate organic matter (POM), but in mineral soils, POM is often a minor pool of N and can be a poor predictor of bioavailable N or plant N uptake. Mounting evidence suggests mineral-associated organic matter (MAOM) is significantly more dynamic than previously assumed and may serve as an important source of N for plants and microbes. The abundance and …

Energy Transfer In The Solar Wind: The Interplay Between Turbulence And Kinetic Instabilities., Simon Opie, Daniel Verscharen, Christopher Chen, Christopher Owen, Philip A. Isenberg, Luca Sorriso-Valvo, Luca Franci, Lorenzo Matteini

Faculty Publications

Precisely how and where energy transfer between scales in the Solar Wind takes place remains an open question. We use the occurrence of conditions predicted by linear theory to promote the growth of kinetic instabilities, to infer how turbulence drives temperature anisotropies. We analyse Solar Orbiter data by applying the measure of local energy transfer (LET) derived from the Politano and Pouquet exact law to identify the relative distributions of energy transfer processes in the solar wind. We quantify these processes with the application of a radial rate of strain computed from single spacecraft data, a measure that we define …

Using Stereo-A Data From April To November 2023 As A Sub-L1 Monitor, Eva Weiler, Christian Möstl, Emma E. Davies, Tanja Amerstorfer, Ute V. Amerstorfer, Hannah T. Rüdisser, Rachel L. Bailey, Astrid Veronig, Timothy Horbury, Noé Lugaz, Justin Le Louëdec, Maike Bauer

Faculty Publications

Sub-L1 monitors are currently being researched in mission concepts for small satellites and may be deployed on distant retrograde orbits around the Earth in the future. Depending on the location of the sub-L1 monitor, the lead time for the arrival of coronal mass ejections (CMEs) and for determining their geo-effectiveness could be prolonged. If the sub-L1 monitor was to orbit the Earth at a distance of 0.05 AU, as is proposed for the MIIST mission, for example, Dst predictions could be made up to 5 hours in advance. The close encounter of STEREO-A and Wind from April 2023 to November …

Energy Transfer In The Solar Wind: The Interplay Between Turbulence And Kinetic Instabilities., Simon Opie, Daniel Verscharen, Christopher Chen, Christopher Owen, Philip A. Isenberg, Luca Sorriso-Valvo, Luca Franci, Lorenzo Matteini

Faculty Publications

Precisely how and where energy transfer between scales in the Solar Wind takes place remains an open question. We use the occurrence of conditions predicted by linear theory to promote the growth of kinetic instabilities, to infer how turbulence drives temperature anisotropies. We analyse Solar Orbiter data by applying the measure of local energy transfer (LET) derived from the Politano and Pouquet exact law to identify the relative distributions of energy transfer processes in the solar wind. We quantify these processes with the application of a radial rate of strain computed from single spacecraft data, a measure that we define …

Now It’S Your Turn!: Eye Blink Rate In A Jenga Task Modulated By Interaction Of Task Wait Times, Effortful Control, And Internalizing Behaviors, Kelley E. Gunther, Xiaoxue Fu Ph.D., Leigha A. Macneill, Morgan Jones, Briana Ermanni, Koraly Pérez-Edgar

Faculty Publications

Dopamine is a versatile neurotransmitter with implications in many domains, including anxiety and effortful control. Where high levels of effortful control are often regarded as adaptive, other work suggests that high levels of effortful control may be a risk factor for anxiety. Dopamine signaling may be key in understanding these relations. Eye blink rate is a non-invasive proxy metric of midbrain dopamine activity. However, much work with eye blink rate has been constrained to screen-based tasks which lack in ecological validity. We tested whether changes in eye blink rate during a naturalistic effortful control task differ as a function of …

The Staggered Retreat Of Grounded Ice In The Ross Sea, Antarctica, Since The Last Glacial Maximum (Lgm), Matthew A. Danielson, Philip J. Bart

Faculty Publications

The retreat of the West Antarctic Ice Sheet (WAIS) in the Ross Sea after the Last Glacial Maximum (LGM) was more significant than for any other Antarctic sector. Here we combined the available chronology of retreat with new mapping of seismically resolvable grounding zone wedges (GZWs). Mapping GZWs is important because they record the locations of former stillstands in the extent of grounded ice for individual ice streams during the overall retreat. Our analysis shows that the longest stillstands occurred early in the deglacial period and had millennial durations. Stillstands ended abruptly with retreat distances measured in the tens to …

Detecting Anomalies In Time Series Using Kernel Density Approaches, Robin Frehner, Kesheng Wu, Alexander Sim, Jinoh Kim

Faculty Publications

This paper introduces a novel anomaly detection approach tailored for time series data with exclusive reliance on normal events during training. Our key innovation lies in the application of kernel-density estimation (KDE) to scrutinize reconstruction errors, providing an empirically derived probability distribution for normal events post-reconstruction. This non-parametric density estimation technique offers a nuanced understanding of anomaly detection, differentiating it from prevalent threshold-based mechanisms in existing methodologies. In post-training, events are encoded, decoded, and evaluated against the estimated density, providing a comprehensive notion of normality. In addition, we propose a data augmentation strategy involving variational autoencoder-generated events and a smoothing …

Computational Design Of An Electro-Organocatalyst For Conversion Of Co2 Into Formaldehyde, Foroogh Khezeli, Craig Plaisance

Faculty Publications

Density functional theory calculations employing a hybrid implicit/explicit solvation method were used to explore a new strategy for electrochemical conversion of CO2 using an electro-organocatalyst. A particular structural motif is identified that consists of an electron-rich vicinal enediamine (>N-C═C-N<) backbone, which is capable of activating CO2 by the formation of a C-C bond while subsequently facilitating the transfer of electrons from a chemically inert cathode to ultimately produce formaldehyde. Unlike transition metal-based electrocatalysts, the electro-organocatalyst is not constrained by scaling relations between the formation energies of activated CO2 and adsorbed CO, nor is it expected to be active for the competing hydrogen evolution reaction. The rate-limiting steps are found to occur during two proton-coupled electron transfer (PCET) sequences and are associated with the transfer of a proton from a proton transfer mediator to a carbon atom on the electro-organocatalyst. The difficulty of this step in the second PCET sequence necessitates an electrode potential of −0.85 V vs RHE to achieve the maximum turnover frequency. In addition, it is postulated that the electro-organocatalyst should also be capable of forming long-chain aldehydes by successively carrying out reductive aldol condensation to grow the alkyl chain one carbon at a time.

Enriched Regions Of 228Ra Along The U.S. Geotraces Pacific Meridional Transect (Gp15), Willard S. Moore, Matt Charette, Paul Henderson, Doug Hammond, Nathaniel Kemnitz, Emilie Leroy, Eun Young Kwon, Mikael Hult

Faculty Publications

The half‐life of 228Ra (5.7 years) aligns well with near‐surface and near‐bottom ocean mixing timescales. Because 228Ra is sourced from sediments, regions of enhanced activity represent water that has recently interacted with sediments on the continental margin or seabed. The GP15 meridional transect from Alaska to Tahiti along152°W encountered several regions in the upper ocean where 228Ra was enriched. These enrichments follow surface and subsurface ocean current patterns and pair with earlier measurements of 228Ra and transient radionuclides to reveal the origins of these enriched regions. An enriched region at Alaska margin stations 1–3 was sourced locally but did not …

Assessing Forage Research And Education Needs Of Organic Dairy Farms In The United States, Eric Hatungimana, Heather M. Darby, Kathy J. Soder, Sara E. Ziegler, Andre F. Brito, Lisa Kissing Kucek, Heathcliffe Riday, E Charles Brummer

Faculty Publications

The viability of organic dairy operations in the United States (US) relies on forage production. The objectives of this study were to (1) assess producer and farm information regarding current forage production practices and producer knowledge gaps and (2) identify forage research and educational needs of organic dairy producers across the US. A survey was distributed to 643 organic dairy producers across the US, with 165 respondents (26% response rate). A focus group consisting of extension professionals, university researchers and staff, consultants, dairy industry representatives and organic dairy producers was also consulted for forage research needs. Results showed that approximately …

Assessing Forage Research And Education Needs Of Organic Dairy Farms In The United States, Eric Hatungimana, Heather M. Darby, Kathy J. Soder, Sara E. Ziegler, Andre F. Brito, Lisa Kissing Kucek, Heathcliffe Riday, E Charles Brummer

Faculty Publications

The viability of organic dairy operations in the United States (US) relies on forage production. The objectives of this study were to (1) assess producer and farm information regarding current forage production practices and producer knowledge gaps and (2) identify forage research and educational needs of organic dairy producers across the US. A survey was distributed to 643 organic dairy producers across the US, with 165 respondents (26% response rate). A focus group consisting of extension professionals, university researchers and staff, consultants, dairy industry representatives and organic dairy producers was also consulted for forage research needs. Results showed that approximately …

Centrifugal Forces Impacting Urbanization In The Eastern Mediterranean During Roman And Early Islamic Times, Øystein S. Labianca

Faculty Publications

My goal with this essay is to make the existence of a distinctive Levantine cultural paradigm a lens through which to examine long-term patterns of urbanization and cultural change in the Eastern Mediterranean—focusing especially on present-day Israel, Jordan and the Palestinian territories. Inspired by the agenda and approach of global history, the essay is an attempt to highlight a number of salient features of societal formation processes in this region that set them apart from such processes in the heartlands of ancient Egypt and Mesopotamia. The paradigm holds that societal formation dynamics in the Levant have been dominated more by …

Graph Theory And Graph Neural Network Assisted High-Throughput Crystal Structure Prediction And Screening For Energy Conversion And Storage, Joshua Ojih, Mohammed Al-Fahdi, Yagang Yao, Jianjun Hu, Ming Hu

Faculty Publications

Prediction of crystal structures with desirable material properties is a grand challenge in materials research, due to the enormous search space of possible combinations of elements and their countless arrangements in 3D space. Despite the recent progress of a few crystal structure prediction algorithms, most of those methods only target a few specific material families or are restricted to simple systems with limited element diversity. Moreover, these algorithms are usually coupled with first principles calculations and thus are computationally expensive and very time consuming. Therefore, establishing a workflow that can generate a large number of hypothetical structures with diverse elements …

Forest Degradation Contributes More To Carbon Loss Than Forest Cover Loss In North American Boreal Forests, Ling Yu, Lei Fan, Philippe Ciais, Jingfeng Xiao, Frédéric Frappart, Stephen Sitch, Jingming Chen, Xiangming Xiao, Rasmus Fensholt, Zhongbing Chang, Hongqian Fang, Xiaojun Li, Tiangxiang Cui, Mingguo Ma, Jean-Pierre Wigneron

Faculty Publications

The carbon sinks of North American boreal forests have been threatened by global warming and forest disturbances in recent decades, but knowledge about the carbon balance of these forests in recent years remains unknown. We tracked annual aboveground carbon (AGC) changes from 2016 to 2021 across the forest regions of NASA's Arctic Boreal Vulnerability Experiment (ABoVE) core study domain, using Vegetation Optical Depth derived from low-frequency passive microwave observations. The results showed that these forests showed a net AGC increase of + 28.49 Tg C/yr during the study period, with total AGC gains of + 219.34 Tg C/yr counteracting total …

Forest Degradation Contributes More To Carbon Loss Than Forest Cover Loss In North American Boreal Forests, Ling Yu, Lei Fan, Philippe Ciais, Jingfeng Xiao, Frédéric Frappart, Stephen Sitch, Jingming Chen, Xiangming Xiao, Rasmus Fensholt, Zhongbing Chang, Hongqian Fang, Xiaojun Li, Tiangxiang Cui, Mingguo Ma, Jean-Pierre Wigneron

Faculty Publications

The carbon sinks of North American boreal forests have been threatened by global warming and forest disturbances in recent decades, but knowledge about the carbon balance of these forests in recent years remains unknown. We tracked annual aboveground carbon (AGC) changes from 2016 to 2021 across the forest regions of NASA's Arctic Boreal Vulnerability Experiment (ABoVE) core study domain, using Vegetation Optical Depth derived from low-frequency passive microwave observations. The results showed that these forests showed a net AGC increase of + 28.49 Tg C/yr during the study period, with total AGC gains of + 219.34 Tg C/yr counteracting total …